Disk drives are information storage devices that use thin film magnetic media to store data. Referring to FIG. 1, a typical disk drive in prior art comprises a head stack assembly (HSA) 104 with slider(s) 203 thereon, a magnetic disk 101 mounted on a spindle motor 102 which causes the magnetic disk 101 to spin, and a motor base 109 to enclose the above-mentioned components. The slider(s) 203 flies over the surface of the magnetic disk 101 at a high velocity to read data from or write data to concentric data tracks on the magnetic disk 101, which is positioned radially by a voice coil 106 embedded (e.g. by epoxy potting or overmolding) in a fantail spacer 108 of the HSA 104. Generally, a voice coil motor (VCM) 107 is used to drive the voice coil 106.
Referring to FIGS. 3(a) and 3(b), a traditional HSA 100 comprises two head gimbal assemblies (HGAs) 201 and 208, a fantail spacer 205 interposed between the head gimbal assembly (HGA) 201 and the HGA 208, and a plurality of securing means to couple the two HGAs 201 and 208 with the fantail spacer 205 together. A flexible printed circuit (FPC) 207 aligns with the fantail spacer 205 by a FPC assembly 217 to electrically connect with the two HGAs 201 and 208. Also, the FPC assembly 217 is provided a plurality of FPC pads 98 thereon. In the related art, the plurality of securing means comprises a bearing 211, a washer 213 and a nut 215. In addition, two mounting holes 221, 228 are formed in the two HGAs 201 and 208, respectively. In the fantail spacer 205 a mounting hole 225 forms corresponding to the mounting holes 221 and 228. These mounting holes 221, 228 and 225 are provided to permit the bearing 211 extend therethrough so as to combine the above-mentioned components together with the help of the washer 213 and the nut 215.
In the prior art, also referring to FIGS. 3(a) and 3(b), the HGA 201 has a suspension flexure cable 231 running from the slider (not labeled) to a trace terminal 241 of the suspension flexure cable 231; similarly, the HGA 208 comprises a suspension flexure cable 238 which terminates with a trace terminal 248. Each of the traces terminals 241 and 248 forms a plurality of terminal pads 99 thereon and each of the terminal pads 99 is shaped as a through-hole.
Referring to FIGS. 3(a)-3(b), when the HSA 100 is assembled, the trace terminals 241 and 248 are positioned on the FPC assembly 217. Then, the HGAs 201 and 208 are electrically connected with the FPC 207 by solder bonding the terminal pads 99 of the trace terminals 241 and 248 with the FPC pads 98 of the FPC assembly 217. After that, with reference to FIG. 2, the HSA 100 is mounted in a motor base 900, and later other essential parts are also assembled in the motor base 900 to form a disk drive unit.
However, the traditional method to connect HGA with FPC by solder bonding can result in component contamination. To avoid component contamination, it is necessary to clean the HSA after solder bonding and yet such cleaning is rather difficult and costly because the bearing has some lubricant thereon and can not clean by water. More seriously, the solder bonding can cause damage to the surrounding electrical components and/or disk media during soldering. In addition, because the HSA must be cleaned before it is mounted in the base plate of the disk drive, so the HSA assembly line and the HDD assembly line cannot be integrated together. That is to say, it must assemble a HSA in HSA assembly line, and then install the HSA into the motor base in HDA assembly line. Furthermore, when there is something wrong with the HGA or the FPC, it must separate the HGA with the FPC for rework, such as repairing or replacing. However, separating the HGA with the FPC is also troublesome because the solders therebetween must be deleted and accordingly reworking the HSA is rather time-consuming and costly. Finally, when there is something wrong with some parts of the HSA, such as HGA, it is required to disassemble the whole HSA from the disk drive unit at first for repairing, accordingly, the cost for reworking the disk drive unit is rather high.
It is therefore desirable to provide a head stack assembly, disk drive unit, and manufacturing method thereof to solve the above-mentioned problems.